BAT SIGNALS The U.S. Navy uses sonar to image underwater objects and obstacles, such as this shipwreck in Narragansett Bay in Rhode Island. Taking inspiration from bats, naval researchers hope to get sharper images with smaller, cheaper sonar equipment.

J. Gaudette, Naval Undersea Warfare Center

IRMA INCOMING Hurricane Irma passed by Cuba on September 8, 2017, as a Category 4 storm (seen in this geocolor image captured by NOAA’s GOES-16 satellite) before making landfall in the Florida Keys on September 10, 2017.

NOAA/CIRA

SMALL BUT DEADLY The potent toxin epibatidine was first discovered in 1974, when it was isolated from the skin of the phantasmal poison frog, Epipedobates anthonyi (one shown).

R. Tarvin/University of Texas at Austin

TANGLED The brain of a person with Alzheimer’s disease symptoms (right) is laden with tau protein (red), while a person with no symptoms (left) has little tau.